Moving to knex

- [x] moving from waterline to knex
- [x] moving from coffeescript to vanilla js
- [x] removing the grunt tasks, moving to the bin CLI convention.
- [x] fix/rewrite tests
- [x] cleanup some old code
- [x] fix documentation
- [x] add a status command
- [ ] add support for cwd param
- [ ] add support for env param

![sails-migrations](https://cloud.githubusercontent.com/assets/231539/4779838/4a588d9e-5c49-11e4-8dfb-a0a9660774c4.gif)